I got a Krieger unused barrel, chambered in 300WM, threaded, and with a black finish for $103 on Ebay... Someone put $450 into it and gave up.. it has 1/2-24 threads on the muzzle.
No brakes have that thread. They are all 1/2-28 or 5/8-24
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. -Ernest Hemingway The man who makes no mistakes does not usually make anything.-- Edward John Phelps